Abstract 17236: Comparative Analysis of Cerebrovascular Resistance in the Fetus with Single Ventricle Type of Congenital Heart Disease
Background: Fetuses with hypoplastic left heart syndrome (HLHS) have altered blood flow patterns to the brain when compared to normal. Whether these findings are also present in other forms of complex single ventricle in which there is unobstructed aortic flow but reduced pulmonary blood flow (SVrp), and the trends of these alterations over the course of gestation, are not known.
Objective: To compare cerebral blood flow patterns in the fetus with single ventricle based on (1) obstruction to aortic flow (HLHS) or (2) unobstructed aortic flow but obstructed pulmonic flow (SVrp), and to assess for trends during gestation.
Methods: Pulsatility indices (PI) were recorded for the middle cerebral artery (MCA) and umbilical artery (UA) in 87 fetuses (209 studies) with HLHS, 29 fetuses (82 studies) with SVrp, and 104 age-matched normal control fetuses (104 studies). The cerebroplacental resistance ratio (CPR) was calculated as the MCA PI/UA PI. Analysis was performed via one-way ANOVA with post-hoc Scheffe testing; trends over the course of gestation were assessed using univariate linear regression.
Results: There was no difference in gestational age (GA) across groups. MCA PI and CPR was significantly lower in the HLHS compared to the SVrp and normal populations. In contrast, MCA-PI was higher in SVrp fetuses compared to normal. Linear regression analysis showed no significant change in MCA-PI for either the normal or SVrp groups, but there was a significant decrease over the course of gestation for the HLHS fetuses (p<0.001).
Conclusions: Within the single ventricle population, variability in anatomy influences fetal cerebral blood flow patterns. In the fetus with HLHS but not SVrp, there is a steady decline in cerebrovascular resistance throughout gestation which may reflect developmental changes. Correlation of these observations to postnatal neurological outcome is warranted.
- © 2010 by American Heart Association, Inc.